1. Field of the Invention
The present invention relates to a zoom lens with a vibration reducing function and more particularly to a vibration reducing method of a photographic lens, a zoom lens for a video camera, etc.
2. Related Background Art
There is a known zoom lens with a vibration reducing function as disclosed in, e.g., Japanese Patent Laid-Open Application No. 1-191113. The zoom lens in Japanese Patent Laid-Open Application No. 1-191113, is formed of two or more lens groups and the whole or a portion of the lens group moved in a zooming operation is shifted in a direction perpendicular to the optical axis to correct a change of an image position due to movement of hands or the like.
In the present invention, to correct the change of the image position due to the movement of the hands or the like by shifting the lens group in the direction perpendicular to the optical axis is called "vibration reduction".
However, in the above prior art, the vibration reducing lens group (the lens group shifted in the direction perpendicular to the optical axis for vibration reduction) is moved along the optical axis in the zooming operation. Therefore, a mechanism for holding the vibration reducing lens group becomes complicated. Further, in the lens system disclosed in Japanese Patent Laid-Open Application No. 1-191113, F-number is about 3.5 to 5.6 and that is, the lens system is dark. Also, a sufficient back focus for a single-lens reflex camera cannot be obtained.